Hydrodynamics of a tropical estuary: Buranhem River, Porto Seguro, Brazil

Rodrigues de Sa Silva, Ana Carolina [UNESP]; Cordeiro Bernardes, Marcos Eduardo; Assireu, Arcilan Trevenzoli; Siegle, Eduardo; Gomes de Oliveira Sousa, Paulo Henrique; Brown, Dustin

Hydrodynamics of a tropical estuary: Buranhem River, Porto Seguro, Brazil

Arquivos

S2318-03312018000100202.pdf (1.3 MB)

Data

2017-01-01

Autores

Rodrigues de Sa Silva, Ana Carolina

Cordeiro Bernardes, Marcos Eduardo

Assireu, Arcilan Trevenzoli

Siegle, Eduardo

Gomes de Oliveira Sousa, Paulo Henrique

Brown, Dustin

Editor

Assoc Brasileira Recursos Hidricos-abrh

Tipo

Artigo

Direito de acesso

Acesso aberto

Resumo

Estuaries are dynamic environments that are highly vulnerable to anthropogenic influences, especially when adjacent to urban areas. In this study it is assessed for the first time the hydrodynamic characteristics of the Buranhem estuary (Northeast Brazil). The aim is to define the salt transport mechanisms and the hydrodynamics and stratification patterns of this tropical estuary, under both spring and neap tidal conditions. Fieldwork was carried out during 8 days covering varying tidal range conditions (July 30th to August 7th, 2015). Salinity and temperature were continuously monitored at moored stations at both the surface and bottom, whereas velocity profile was sampled by a bottom-mounted instrument. Average velocity in the water column was 0.46 m. s(-1) during flood tides and 1.0 m. s(-1) during ebb tides. Residual currents were seaward, with ebb dominance. The dominant salt transport mechanism is turbulent diffusion. Most of the layer Richardson values did not exceed 2, indicating well mixed conditions mainly during spring tides. Stratification varies with tide condition, with spring tides being able to further mix the vertical structure. Vertical velocity gradients that generate vertical mixing overcome the stabilizing effects generated by vertical density gradients.